1. Field of the Invention
The present invention relates to a semiconductor device.
2. Description of the Related Art
In recent years, various proposals about nonvolatile memories have been made (for example, see Jpn. Pat. Appln. KOKAI Publication No. 5-129625). In the nonvolatile memory, in order to secure a sufficient charge retention characteristic, it is important to minimize a leakage current as much as possible.
However, in a conventional nonvolatile memory, it cannot be said that a leakage current though an inter-electrode insulating film is always sufficiently suppressed.